I am performing a simple test of a sparse matrix stores in CRS3 format with sparse_matrix_checker(). When I perform this test in the matrix_check.c MKL example code, it passes as expected. Also, I compiled the examples with GCC.
However, when I perform an identical check in a Matlab C++ MEX function (also compiled with GCC), I get a strange error that doesn't make sense. The matrix is identical to the one given in the MKL documentation at https://software.intel.com/en-us/node/471374. I am using zero-based indexing. Therefore, my row, column and value arrays are:
/* Matrix data. */
MKL_INT n = 5;
MKL_INT ia[6] = {0,3,5,8,11,13};
MKL_INT ja[13] =
{0,1,3,0,1,2,3,4,0,2,3,1,4};
double a[13] =
{1,-1,-3,-2,5,4,6,4,-4,2,7,8,-5};
The parameters of my matrix check are:
pt.n = n;
pt.csr_ia = ia;
pt.csr_ja = ja;
pt.indexing = MKL_ZERO_BASED;
pt.matrix_structure = MKL_GENERAL_STRUCTURE;
pt.print_style = MKL_C_STYLE;
pt.message_level = MKL_PRINT;
Again, when I run this check in matrix_check.c compiled from the examples, it passes. But when I compile this in a Matlab MEX, I get the error:
Matrix check result code: 21 (MKL_SPARSE_CHECKER_NON_MONOTONIC)
Matrix check details: (1, 0, 0)
However, this error doesn't make sense because ia[1] and ia[2] are not zero. Instead, they are 3 and 5. Thus, it seems there is some memory read error by the MKL library.
Note, I am compiling the MEX file with the following compiler options using G++ 4.9.2:
LDFLAGS=-m64 -I/opt/intel/compilers_and_libraries_2016.0.109/linux/mkl/include -L/opt/intel/mkl/lib/intel64 -lmkl_core -lmkl_intel_ilp64 -lmkl_gnu_thread myTest.cpp
Also, I verified that the matrix is in fact stored correctly by reading it out in the Matlab MEX file:
0: val: 1 cols: 0 rows: 0 1: val: -1 cols: 1 rows: 3 2: val: -3 cols: 3 rows: 5 3: val: -2 cols: 0 rows: 8 4: val: 5 cols: 1 rows: 11 5: rows: 13 5: val: 4 cols: 2 6: val: 6 cols: 3 7: val: 4 cols: 4 8: val: -4 cols: 0 9: val: 2 cols: 2 10: val: 7 cols: 3 11: val: 8 cols: 1 12: val: -5 cols: 4
It seems to me that there is some issue caused by the way I am compiling this test that causes the MKL library to access memory differently than how it is being allocated. Does this make sense? Any thoughts or ideas for me to check?
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